Methotrexate

Drug Name : Methotrexate
Indications : Widely used anticancer drug acting as an antimetabolite in DNA synthesis.
Physiology : Methotrexate is an antimetabolite that combines with dihydrofolate reductase and interferese with the synthesis of tetrahydrofolic acid necessary for DNA synthesis.
Normal Values : Normal values depend upon the drug therapy.
Critical Values : >2.27 µg/mL (> 5 µmol/L)
Test Method : Enzyme immunoassay, Radio immunoassay, HPLC
Side effects : Combination of salicylate administration increases incidence of toxicity, due to diminished renal tubular excretion.